This invention relates to the marking of surfaces such as packaging film by signal controlled marking apparatus utilizing ink as the marking medium.
Signal controlled apparatus for marking a traveling web of material is disclosed in my prior U.S. Pat. No. 3,487,776. In this type of apparatus, the traveling web is engaged by a friction driver wheel that is intermittently loaded under control of a signal operated clutch to rotate a printing wheel for marking the traveling web at spaced locations. The print face on the printing wheel while spaced from the traveling web, has ink transferred thereto from an ink storing device. One of the drawbacks associated with the aforementioned marking apparatus resides in the tendency of the web to rupture because of excessive drive pressure exerted thereon by prolonged contact between the web and the friction driver for the rotary printing wheel. Further, engagement of the printing wheel by the ink storing device through which ink is transferred to the printing wheel, imposes a constant drag and that not only requires increased contact pressure on the moving web but also results in excessive wear on the print face.
A web driven, rotary marking device of the aforementioned type is also disclosed in my prior U.S. Pat. No. 3,666,682 employing a replaceable ink cartridge type of ink storing device. The latter type of marking device suffers from the same drawbacks however, as aforementioned.
Replaceable cartridge types of ink storing devices are also disclosed in prior U.S. Pat. Nos. 3,797,390 and 3,804,016 owned in common with the previously mentioned patents. In the latter two mentioned patents, a print head is displaced between a marking position and a rest position with the ink storing device engaging the marking device only in the rest position. However, the print face in its rest position is continuously engaged by the ink storing device.
It is therefore an important object of the present invention to provide a signal operated marking apparatus for a traveling web utilizing a rotatable web driven print head for rapid and automatic operation wherein the aforementioned drawbacks of prior patented marking apparatus are avoided. An additional object of the present invention is to provide a marking device which not only avoids the undesirable features aforementioned in connection with applicant's prior patented devices but also combines the various beneficial features of such prior patented devices in a compatible manner including a rotary print head under signal operated clutch control driven by the traveling web and a replaceable cartridge type of ink storing device that is slidably mounted by the frame of the marking device.